Solid state image pickup device and manufacturing method thereof and semiconductor integrated circuit device and manufacturing method thereof

ABSTRACT

A method of manufacturing a solid-state image pickup device comprises a process for forming a plurality of photoelectric conversion elements PD within a semiconductor substrate  4 , a process for forming an interconnection portion, having an interconnection layer  8  in an insulating layer  7 , on the surface side of the semiconductor substrate  4 , a process for forming an adhesive layer, made of a material cured at a temperature lower than a deterioration starting temperature of the interconnection layer  8 , on the surface of the interconnection portion and bonding a supporting substrate  30  to the surface side of the interconnection portion through the adhesive layer  9  by heat treatment at a temperature lower than the deterioration starting temperature of the interconnection layer  8  and a process for decreasing a thickness of the semiconductor substrate  4  from the back side. A solid-state image pickup device manufacturing method can bond the supporting substrate  30  to the surface side of the interconnection portion through the adhesive layer  9  without exerting a thermal influence upon the interconnection layer  8  that was previously formed on the surface side of the semiconductor substrate  4.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a solid-state image pickup device and amanufacturing method thereof, and a semiconductor integrated circuitdevice and a manufacturing method thereof.

2. Description of the Related Art

A related-art, solid-state image pickup device includes a semiconductorsubstrate in which circuit elements, interconnection layers and the likeare formed on the surface side thereof and in which photodiodes and thelike are formed on the back side thereof to introduce light from thesurface side of the semiconductor substrate to pick up an image.

However, in the case of such an arrangement, incident light is absorbedor reflected on the circuit elements. The interconnection layers and thelike are formed on the surface side of the semiconductor substrate sothat efficiency at which incident light is photoelectrically convertedis low. Thus, sensitivity of the solid-state image pickup device islowered.

Accordingly, in order to solve such a problem, a so-calledback-illuminated type solid-state image pickup device has been proposed,in which circuit elements, interconnection layers and the like areformed on the surface side of the semiconductor substrate; photodiodesare formed on the back side of the semiconductor substrate and light isintroduced from the back side of the semiconductor substrate to pickupan image, to increase an aperture ratio, to receive incident light andto suppress absorption of reflection of incident light (see cited patentreference 1, for example).

On the other hand, since a semiconductor integrated circuit device isprogressively increased in integration degree as elements areincreasingly microminiaturized in recent years, then the number of gatesused in a transistor is increased considerably, and hence the layout ofan interconnection layer for interconnecting the cells of a logiccircuit and for interconnecting the blocks of micro-function becomescomplex.

Although it is desirable that the interconnection layer shouldinterconnect the cells or the blocks with the shortest distance or withan equal distance, depending upon the layout circumstances, it becomesdifficult for the interconnection layer to interconnect the cells or theblocks with the shortest distance or the equal distance.

In order to solve the above-mentioned problem, there has been proposed amethod for forming interconnection layers not only on the surface sideof the semiconductor substrate but also on the back side of thesemiconductor substrate (see cited patent reference 2, for example).

[Cited patent reference 1]: Official gazette of Japanese laid-openpatent application No. 2003-31785

[Cited patent reference 2]: Official gazette of Japanese laid-openpatent application No. 9-260699

In the above-mentioned back-illuminated type solid-state image pickupdevice, in order to introduce incident light from the back side of thesemiconductor substrate, the back side of the semiconductor substrateshould be decreased in film thickness after the circuit elements and thephotodiodes and the like are formed on the front side of thesemiconductor substrate.

However, when the back side of the semiconductor substrate is decreasedin film thickness, it is unavoidable that flatness of the semiconductorsubstrate cannot be obtained due to stress inherent in the semiconductorsubstrate and that the semiconductor substrate becomes weak from amechanical standpoint.

Accordingly, as a method for solving such a problem, a supportingsubstrate is to be bonded to the semiconductor substrate before the backside of the semiconductor substrate is decreased in film thickness.

Manufacturing processes for manufacturing the back-illuminated typesolid-state image pickup device according to this method will bedescribed with reference to FIGS. 1A to 1F.

First, as shown in FIG. 1A, there is prepared an SOI (silicon oninsulator) substrate 65 in which a single crystal silicon layer(so-called SOI layer) 64 is formed on a silicon substrate 62 through aburied oxide film (so-called BOX layer) 63, for example.

Next, a photodiode PD is formed on the SOI substrate 65 at thepredetermined position within the single crystal silicon layer 64.

Then, a MOS (metal-oxide semiconductor) type transistor Tr1 and a CMOS(complementary MOS) type Tr2, each of which comprises a gate electrode66 and a pair of a source region and a drain region, are formed on thesingle crystal silicon layer 64 at the predetermined positions throughan insulating film (not shown), thereby exhibiting the state shown inFIG. 1B.

Next, a multilayer interconnection layer 68 (681, 682, 683) is formed onthe single crystal silicon layer 64 at the positions corresponding tothe MOS type transistor Tr1 and the CMOS type transistor Tr2 through aninsulating layer 67, thereby exhibiting the state shown in FIG. 1C.

Next, a planarized film (not shown) is formed on the insulating layer67, and a supporting substrate 70 is attached to the insulating layer 67by coating an adhesive layer 69 on this planarized layer, therebyexhibiting the state shown in FIG. 1D.

Next, this back-illuminated type solid-state image pickup device isreversed up and down and thereby the back side of the SOI substrate 65,that is, the silicon substrate 62 is exposed.

Then, the exposed silicon substrate 62 and the buried oxide film 63 areremoved, whereby the single crystal silicon layer 64 of the SOIsubstrate 65 is exposed as shown in FIG. 1E.

After that, as shown in FIG. 1F, an insulating film 72, anantireflection film, a planarized film (not shown) and the like areformed on the back side of the single crystal silicon layer 64, and anon-chip microlens 74 is formed on back side of the single crystalsilicon layer 64 at its portion corresponding to the photodiode PDthrough a color filter 73.

In this manner, there can be obtained a back-illuminated type CMOSsolid-state image pickup device 60.

In the process in which the supporting substrate 70 is bonded to theinsulating layer 67 by coating the adhesive layer 69 on the insulatinglayer 67 on the semiconductor substrate 64 as was shown in FIG. 1D, theheat treatment is carried out in order to cure the adhesive layer 69 orto increase bonding strength at which the supporting substrate 70 isbonded to the insulating layer 67.

However, when this heat treatment is carried out at a high temperatureranging from 900° F. to 1100° F. under which temperature the SOIsubstrate has been manufactured so far, for example, it is unavoidablethat a thermal influence is exerted upon the multilayer interconnectionlayer 68 (681, 682, 683) previously formed on the surface side of thesingle crystal silicon layer 64 and which is made of a material with lowheat-resistance (Al, Cu and the like).

Also, although there is known a method of using boron phosphorussilicate glass (BPSG), phosphorus silicate glass (PSG), boron silicateglass (BSG) and the like as the material of the adhesive layer 69, sincethis method also uses heat treatment at a temperature ranging of from700° C. to 900° C., it is unavoidable that a thermal influence isexerted upon the interconnection layer 68 (681, 682, 683) which waspreviously formed on the surface side of the single crystal siliconlayer 64.

Accordingly, these high temperature heat treatments cannot be applied tothe case in which the back-illuminated type solid-state image pickupdevice is manufactured.

Further, there is known a method of using coated glass (SOG) as thematerial of the adhesive layer 69 because the coated glass (SOG) canrealize a planarized layer.

However, in this case, in the thin film forming processes shown in FIGS.1D and 1E, if wet etching process is carried out, then the SOG iscorroded (etched) by liquid medicine and hence bonding strength islowered.

Further, uneven coated portions are formed depending upon the kind ofthe material of the adhesive layer 69 so that holes, voids and the likeare formed on the interface in which the insulating layer 67 and thesupporting substrate 70 are bonded together.

Also, there is proposed a method of directly bonding the single crystalsilicon layer 64 and the supporting substrate 70 without coating theadhesive layer 69 on the insulating layer 67. According to this knownmethod, since the heat treatment is carried out at 1000° C. for 10hours, it is unavoidable that a thermal influence is exerted upon theinterconnection layer 68 (681, 682, 682) which was previously formed onthe surface side of the semiconductor substrate.

Further, there is proposed a method of bonding the single crystalsilicon layer 64 and the supporting substrate 70 by using an adhesivetape without coating the adhesive layer 69 on the insulating layer 67.In this case, if a thick adhesive tape is used, then a problem in whichthe adhesive tape is torn off does not arise. However, since theadhesive tape is warped considerably after the heat treatment, a problemarises, in which an exposure process cannot be made in the followingmanufacturing processes.

While the case in which the solid-state image pickup device ismanufactured from the SOI substrate 65 composed of a plurality of layershas been described so far by way of example, a similar problem arisesalso in the case in which the solid-state image pickup device having theabove-mentioned arrangement is manufactured from a single layer of asilicon substrate, for example.

Also, not only in the above-mentioned back-illuminated type solid-stateimage pickup device but also in a semiconductor integrated circuitdevice, it is considered that a multilayer interconnection layer may beformed on the semiconductor substrate on which the circuit elements areformed.

Then, when such semiconductor integrated circuit device is manufactured,in order to obtain desired characteristics in the circuit elements suchas transistors, it is frequently observed that the semiconductorsubstrate with the circuit elements formed thereon should be decreasedin thickness.

Accordingly, in such a case, a problem similar to that of the case inwhich the back-illuminated type solid-state image pickup device ismanufactured arises unavoidably.

SUMMARY OF THE INVENTION

In view of the aforesaid aspect, it is an object of the presentinvention to provide a solid-state image pickup device manufacturingmethod in which a supporting substrate can be bonded to aninterconnection portion through an adhesive layer without exertingthermal influence upon an interconnection layer that was previouslyformed on the surface side of a semiconductor substrate.

It is another object of the present invention to provide a solid-stateimage pickup device in which a supporting substrate can be bonded to aninterconnection portion through an adhesive layer without exerting athermal influence upon an interconnection layer that was previouslyformed on the surface side of a semiconductor substrate.

It is a further object of the present invention to provide asemiconductor integrated circuit device manufacturing method in which asupporting substrate can be bonded to an interconnection portion throughan adhesive layer without exerting a thermal influence upon aninterconnection layer that was previously formed on the surface side ofa semiconductor substrate.

It is yet a further object of the present invention to provide asemiconductor integrated circuit device in which a supporting substratecan be bonded to an interconnection portion through an adhesive layerwithout exerting a thermal influence upon an interconnection layer thatwas previously formed on the surface side of a semiconductor substrate.

According to an aspect of the present invention, there is provided amethod of manufacturing a solid-state image pickup device which iscomprised of a process for forming a plurality of photoelectricconversion elements within a semiconductor substrate, a process forforming an interconnection portion, having an interconnection layer inan insulating layer, on the surface side of the semiconductor substrate,a process for forming an adhesive layer, made of a material cured at atemperature lower than a deterioration starting temperature of theinterconnection layer, on the surface side of the interconnectionportion and bonding a supporting substrate to the insulating layerthrough the adhesive layer by heat treatment at a temperature lower thanthe deterioration starting temperature of the interconnection layer anda process for decreasing a thickness of the semiconductor substrate fromthe back side.

According to a method of manufacturing a solid-state image pickup deviceof the present invention, since this solid-state image pickup devicemanufacturing method includes the process for forming a plurality ofphotoelectric conversion elements within the semiconductor substrate,the process for forming the interconnection portion, having theinterconnection layer in the insulating layer, on the surface side ofthe semiconductor substrate and the process for forming the adhesivelayer, made of the material cured at the temperature lower than thedeterioration starting temperature of the interconnection layer, on thesurface side of the interconnection portion and bonding the supportingsubstrate to the insulating layer through the adhesive layer by heattreatment at the temperature lower than the deterioration startingtemperature of the interconnection layer and the process for decreasingthe thickness of the semiconductor substrate from the back side, in theprocess for bonding the supporting substrate to the surface of theinterconnection portion through the adhesive layer, the adhesive layercan be cured by the heat treatment at the temperature lower than thedeterioration starting temperature of the interconnection layer that wasformed previously. Thus, the supporting substrate can be bonded to thesurface side of the interconnection portion through the adhesive layerwithout exerting a thermal influence upon the interconnection layer thatwas previously formed on the surface side of the semiconductorsubstrate.

According to another aspect of the present invention, there is provideda solid-state image pickup device which is comprised of a semiconductorsubstrate, a plurality of photoelectric conversion elements formedwithin the semiconductor substrate, an interconnection portion, havingan interconnection layer in an insulating layer, formed on the surfaceside of the semiconductor substrate and a supporting substrate bonded tothe surface side of the interconnection portion through an adhesivelayer, wherein the adhesive layer is made of a material cured at atemperature lower than a deterioration starting temperature of theinterconnection layer.

According to a solid-state image pickup device of the present invention,since this solid-state image pickup device is comprised of asemiconductor substrate, a plurality of photoelectric conversionelements formed within the semiconductor substrate, the interconnectionportion, having the interconnection layer in the insulating layer,formed on the surface side of the semiconductor substrate and thesupporting substrate bonded to the surface side of the interconnectionportion through the adhesive layer, wherein the adhesive layer is madeof the material cured at the temperature lower than the deteriorationstarting temperature of the interconnection layer, upon manufacturing,the adhesive layer can be cured by the heat treatment at the temperaturelower than the deterioration starting temperature of the interconnectionlayer that was formed previously. Thus, in the process for bonding thesupporting substrate to the interconnection portion through the adhesivelayer, it is possible to protect the interconnection layer formed on thesurface side of the semiconductor substrate from being affectedthermally.

According to a further aspect of the present invention, there isprovided a method of manufacturing a semiconductor integrated circuitdevice which is comprised of a process for forming a circuit element ona semiconductor substrate, a process for forming an interconnectionportion, having an interconnection layer in an insulating layer, on thesurface side of the semiconductor substrate and a process for forming anadhesive layer, made of a material cured at a temperature lower than adeterioration starting temperature of the interconnection layer, on thesurface side of the interconnection portion and bonding a supportingsubstrate to the interconnection portion through the adhesive layer byheat treatment at a temperature lower than the deterioration startingtemperature of the interconnection layer.

According to a method of manufacturing a semiconductor integratedcircuit device of the present invention, since this semiconductorintegrated circuit device manufacturing method is comprised of theprocess for forming the circuit element on the semiconductor substrate;the process for forming the interconnection portion, having theinterconnection layer in the insulating layer, on the surface side ofthe semiconductor substrate; and the process for forming an adhesivelayer, made of the material cured at the temperature lower than thedeterioration starting temperature of the interconnection layer, on thesurface side of the interconnection portion and bonding the supportingsubstrate to the interconnection portion through the adhesive layer bythe heat treatment at the temperature lower than the deteriorationstarting temperature of the interconnection layer, in the process forbonding the supporting substrate to the interconnection portion throughthe adhesive layer, the adhesive layer can be cured by the heattreatment at the temperature lower than the deterioration startingtemperature of the interconnection layer that was formed previously.Thus, it is possible to bond the supporting substrate to theinterconnection portion through the adhesive layer without exerting athermal influence upon the interconnection layer that was previouslyformed on the surface side of the semiconductor substrate.

In accordance with yet a further aspect of the present invention, thereis provided a semiconductor integrated circuit device which is comprisedof a circuit element formed within a semiconductor substrate, aninterconnection portion, having an interconnection layer in aninsulating layer, formed on the surface side of the semiconductorsubstrate and a supporting substrate bonded to the surface side of theinterconnection portion through an adhesive layer, wherein the adhesivelayer is made of a material cured at a temperature lower than adeterioration starting temperature of the interconnection layer.

According to the semiconductor integrated circuit device of the presentinvention, since this semiconductor integrated circuit device iscomprised of the circuit element formed within the semiconductorsubstrate, the interconnection portion, having the interconnection layerin the insulating layer, formed on the surface side of the semiconductorsubstrate and the supporting substrate bonded to the surface side of theinterconnection portion through the adhesive layer, wherein the adhesivelayer is made of the material cured at the temperature lower than thedeterioration starting temperature of the interconnection layer, uponmanufacturing, the adhesive layer can be cured by the heat treatment atthe temperature lower than the deterioration starting temperature of theinterconnection layer that was formed previously. Thus, in the processfor bonding the supporting substrate to the interconnection portionthrough the adhesive layer, it is possible to protect theinterconnection layer formed on the surface side of the semiconductorsubstrate from being affected thermally.

According to the solid-state image pickup device manufacturing methodand the semiconductor integrated circuit device manufacturing method ofthe present invention, the supporting substrate can be bonded to theinterconnection portion without exerting a thermal influence upon theinterconnection layer that was formed previously. Therefore, it ispossible to manufacture the solid-state image pickup device and thesemiconductor integrated circuit device with excellent characteristics.

According to the semiconductor solid-state image pickup device and thesemiconductor integrated circuit device of the present invention, whenthe supporting substrate is bonded to the interconnection portionthrough the adhesive layer, it is possible to avoid a thermal influencefrom being exerted upon the previously-formed interconnection layer.Therefore, it is possible to realize the highly-reliable solid-stateimage pickup device and semiconductor integrated circuit device withhigh performance.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A to 1F are manufacturing process diagrams showing amanufacturing method of a solid-state image pickup device according tothe related art, respectively;

FIG. 2 is a schematic cross-sectional view showing a solid-state imagepickup device according to an embodiment of the present invention;

FIG. 3 is a cross-sectional view showing a main portion of FIG. 2 in anenlarged-scale;

FIGS. 4A to 4C are diagrams of chemical formulas used to explainprogress of a crosslinking reaction, respectively;

FIGS. 5A to 5G are manufacturing process diagrams showing amanufacturing method of a solid-state image pickup device shown in FIGS.2 and 3, respectively;

FIG. 6 is a schematic cross-sectional view showing a semiconductorintegrated circuit device according to an embodiment of the presentinvention;

FIG. 7 is a cross-sectional view showing a main portion of FIG. 6 in anenlarged-scale;

FIGS. 8A to 8G are manufacturing process diagrams showing amanufacturing method of a semiconductor integrated circuit device shownin FIGS. 6 and 7, respectively;

FIG. 9 is a schematic cross-sectional view showing a semiconductorintegrated circuit device according to other embodiment of the presentinvention;

FIG. 10 is a schematic cross-sectional view showing a semiconductorintegrated circuit device according to a further embodiment of thepresent invention; and

FIG. 11 is a schematic cross-sectional view showing a semiconductorintegrated circuit device according to yet a further embodiment of thepresent invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will now be described below with reference to thedrawings.

First, a solid-state image pickup device according to an embodiment ofthe present invention, for example, a CMOS (complementary metal-oxidesemiconductor) solid-state image pickup device will be described withreference to FIGS. 2 and 3.

FIG. 2 is a schematic diagram (cross-sectional view) of a CMOS typesolid-state image pickup device, and FIG. 3 is a cross-sectional viewshowing a main portion of FIG. 2 in an enlarged-scale. A color filterand an on-chip microlens are not shown in FIG. 2.

As shown in FIGS. 2 and 3, in a CMOS type solid-state image pickupdevice 10 according to the embodiment of the present invention, an imagepickup region 24 includes a single crystal silicon layer (semiconductorsubstrate) 4 in which unit pixels 22, each of which is composed of aphotoelectric conversion element (photodiode PD) and a plurality of MOStype transistors Tr1, are arranged in an XY matrix fashion(two-dimensional fashion). Further, in a peripheral region 25, aperipheral circuit portion 23 composed of a plurality of CMOS typetransistors Tr2 is formed on the semiconductor substrate 4.

Although not shown, in addition to the image pickup region 24 and theperipheral region 25, there is formed a region in which a pad connectedto an external interconnection, for example, is provided.

The MOS type transistor Tr1 formed on the unit pixel 22 has anarrangement in which a gate electrode 6 is formed between a pair of asource region and a drain region (not shown) formed on the semiconductorsubstrate 4 through a gate insulating film.

Also, the CMOS type transistor Tr2 of the peripheral circuit portion 23has the similar arrangement in which a gate electrode 6 is formedbetween a pair of a source region and a drain region (not shown) formedon the semiconductor substrate 4 through a gate insulating film.

A multilayer interconnection layer 8 (81, 82, 83) is formed on thesurface side (lower side in FIG. 3) of the image pickup region 24 andthe peripheral region 25 of the semiconductor substrate 4.

On the other hand, a antireflection film, a planarized film and the likeare formed on the back side (in the upper side of FIG. 3) of thesemiconductor substrate 4 through the insulating film 32, and theon-chip microlens 34 is formed on the semiconductor substrate 4 throughthe color filter 33 in correspondence with the photodiode PD of eachunit pixel 22.

In the CMOS type solid-state image pickup device 10 having such anarrangement, light is irradiated on the photodiode PD from the back sideof the semiconductor substrate 4 through the on-chip microlens 34.

Then, in the solid-stage image pickup device 10 according to thisembodiment, in particular, the adhesive layer 9 is made of a materialthat can be cured at a temperature lower than a deterioration startingtemperature of the interconnection layer 8 (81, 82, 83) previouslyformed on the semiconductor substrate 4 and which is made of a materialwith low heat-resistance (for example, Al or Cu).

To be more concrete, when the interconnection layer 8 is made of Al orCu, for example, the adhesive layer 9 is made of a material that can becured at a temperature lower than 450° C.

A coating film made of benzocyclobutene (BCB), for example, is availableas such material.

Benzocyclobutene has properties in which a crosslinking reaction(curing) proceeds at a low temperature ranging of from 150° C. to 250°C.

The progress of the crosslinking reaction will hereinafter be describedwith reference to curing reaction formulas of benzocyclobutene shown inFIGS. 4A to 4C. FIGS. 4A to 4C show curing reaction formulas insomewhere of the progress of the crosslinking reaction, respectively.

A structural formula of benzocyclobutene in the state in which it is notprocessed by heat treatment (that is, monomer) is expressed as shown inFIG. 4A. In the state (monomer state) shown in FIG. 4A, cyclobutenerings 351, 352 are bonded to respective benzene rings, respectively.

Next, with application of heat treatment, a ring opening reaction occursin the cyclobutene ring 352 and a carbon double-bond 36 is formed asshown in FIG. 4B. Then, other benzocyclobutene is bonded to this carbondouble-bond (Deils-Alder reaction). The ring opening reaction is startedat a temperature of approximately 150° C. and its chemical reaction ismade active at a temperature in excess of 200° C.

As a result, as shown in FIG. 4C, there is exhibited the state in whichbenzocyclobutene is polymerized. In the state shown in FIG. 4C, thecyclobutene rings 351, 352 and 354 are respectively bonded to therespective benzene rings.

In accordance with a further progress of heat treatment, the respectivereactions shown in FIGS. 4A to 4C are being repeated, thereby resultingin benzocyclobutene being cured progressively.

In addition to the above-mentioned properties, benzocyclobutene hasproperties in which it becomes low in viscosity with application of heattreatment. In this case, since reflowing properties can be enhanced, itbecomes possible to planarize the substrate, for example.

Also, since benzocyclobutene has high chemical-resistance, it isdifficult to be corroded (etched) by liquid medicine and hence bondingstrength can be maintained.

As described above, according to the solid-state image pickup device 10of this embodiment, since the adhesive layer 9 is made ofbenzocyclobutene which can be cured at the temperature ranging of from150° C. to 250° C. lower than the deterioration starting temperature ofthe previously-formed interconnection layer 8 (81, 82, 83), in themanufacturing process which will be described later on, when thesupporting substrate 4 is bonded to the single crystal silicon layer 4,it becomes possible to protect the interconnection layer 8 (81, 82, 83)made of Al or Cu which is low in heat-resistance from being affectedthermally even with application of heat treatment for curing theadhesive layer 9.

Also, since benzocyclobutene becomes low in viscosity and it becomeshigh in reflowing properties with application of heat treatment, itbecomes possible to improve the close contact between the insulatinglayer 7 and the supporting substrate 30. As a result, it becomespossible to suppress the occurrence of holes, voids and the like at theinterface between the insulating layer 7 and the supporting substrate 30are bonded together.

Further, since the surface of the insulating layer 7 can be planarized,it becomes possible to bond the insulating layer 7 and the supportingsubstrate 30 together with flatness.

Next, a method of manufacturing the solid-state image pickup device 10having the above-mentioned arrangement will be described with referenceto FIGS. 5A to 5G. In FIGS. 5A to 5G, elements and parts identical tothose of FIGS. 2 and 3 are marked with identical reference numerals andtherefore need not be described.

First, as shown in FIG. 5A, an SOI substrate 5 with the single crystalsilicon layer 4 formed thereon is prepared on the silicon substrate 2,for example, through the buried oxide film (so-called BOX layer) 3.

Film thicknesses of the buried oxide film 3 and the single crystalsilicon layer 4 can be set arbitrarily.

Next, as shown in FIG. 5B, the photodiode PD is formed on the SOIsubstrate 5 at the predetermined position within the single crystalsilicon layer 4.

Next, the gate electrode 6 and the MOS type transistor Tr1 and the CMOStype transistor Tr2, each of which is composed of a pair of a sourceregion and a drain region, though not shown, are formed on the imagepickup region 24 and the peripheral region 25 of the single crystalsilicon layer 4 through an insulating layer (not shown), therebyexhibiting the state shown in FIG. 5C.

Next, as shown in FIG. 5D, the multilayer interconnection layer 8 isformed on the image pickup region 24 and the peripheral region 25 of thesingle crystal silicon layer 4.

More specifically, first, after the insulating layer 7 was formed on theimage pickup region 24 and the peripheral region 25 of the singlecrystal silicon layer 4 and processed by planarization treatment, theinterconnection layer 81 which becomes the first layer is formed with apredetermined pattern.

Next, after the insulating layer 7 was again formed on the whole surfaceincluding the interconnection layer 81 of the first layer and theelectrode layer 29 and processed by planarization treatment, theinterconnection layer 82 which becomes the second layer is formed with apredetermined pattern.

Next, after the insulating layer 7 was again formed on the whole surfaceincluding the interconnection layer 82 of the second layer and processedby planarization treatment, the interconnection layer 83 which becomesthe third layer is formed with a predetermined pattern.

While the interconnection layer 8 has the trilayer structure as shown inFIG. 5D, when the interconnection layer 8 is formed so as to have amultilayer structure having layers more than three layer, theabove-mentioned processes may be repeated.

Further, according to the need, it is possible that a planarized filmformed of an SiN film, an SiON film and the like will be formed in thelater process.

Next, as shown in FIG. 5E, the adhesive layer 9 is coated on theinsulating layer 7 and the supporting substrate 30 is bonded to theinsulating layer 7 through the adhesive layer 9.

In this embodiment, the adhesive layer 9 made of benzocyclobutene isformed and thereby the supporting substrate 30 is bonded to theinsulating layer 7.

Then, the single crystal silicon layer 4 and the supporting substrate 30bonded to each other by the adhesive layer 9 was heated and pressed withpressure within a vacuum chamber, whereby the adhesive layer 9 is curedto cause the single crystal silicon layer 4 and the supporting substrate30 to contact with each other closely.

Under specific bonding conditions of a reduced-pressure atmosphere of10⁻² Torr and a heating temperature of 350° C., the single crystalsilicon layer 4 and the supporting substrate 30 are bonded together bypress treatment with pressure of 1000N for 5 minutes.

In that case, the adhesive layer 9 starts being cured in a lowtemperature region ranging of from 150° C. to 200° C. As a consequence,it is possible to prevent the interconnection layer 8 (81, 82, 83) madeof the material (Al or Cu) with low heat-resistance that was previouslyformed on the semiconductor substrate 4 from being affected thermally.

Also, since the adhesive layer 9 is spread over a wide range of theinsulating layer 7, uneven coated portions can be avoided and hence theclose contact between the insulating layer 7 and the supportingsubstrate 30 can be increased. Further, difference in level produced onthe surface of the insulating layer 7 can be restored and the surface ofthe insulating layer 7 can be made flat.

After that, the resultant product is inverted up and down and hence theback side of the SOI substrate 5, that is, the silicon substrate 2 isexposed. Then, the exposed silicon substrate 2 and the buried oxide film3 are removed by a back-grinder method, for example, and thereby thefilm thickness is decreased to such one which falls within a range offrom approximately 15 nm to 20 nm, for example. Thus, as shown in FIG.5F, there is exhibited the state in which the single crystal siliconlayer 4 of the SOI substrate 5 is exposed.

The film thickness can be decreased by not only the back-grinder methodbut also other suitable method such as a CMP (chemical mechanicalpolish) method and a wet etching process. When the wet etching processis in use, since benzocyclobutene has high chemical resistance, it ispossible to prevent the adhesive layer 9 from being corroded (etched) byliquid medicine.

Then, as shown in FIG. 5G, an antireflection film, a planarized film andthe like, for example, are formed on the back side of the single crystalsilicon layer 4 and the on-chip microlens 34 is formed on the singlecrystal silicon layer 4 at the portion corresponding to the photodiodePD through the color filter 33.

In this manner, there can be manufactured the back-illuminated type CMOSsolid-state image pickup device 10 having the arrangement shown in FIG.3.

While the silicon substrate 2 and the buried oxide film 3 are removedand the single crystal silicon layer 4 of the SOI substrate 5 is exposedin the manufacturing processes shown in FIGS. 5E to 5F, the presentinvention is not limited thereto and the buried oxide film (insulatingfilm) 3 can be left by removing only the silicon substrate 2.

According to the above-mentioned manufacturing method, as shown in FIG.5E, since the coating film made of benzocyclobutene is formed on theinsulating layer 7 as the adhesive layer 9 and the supporting substrate30 is bonded to the insulating layer 7, curing of the coating film mayproceed at the low temperature ranging of from 150° C. to 200° C. Thus,it is possible to suppress a thermal influence from being exerted uponthe interconnection layer 8 (81, 82, 83) previously formed on thesemiconductor substrate 4 and which is made of the material with lowheat-resistance.

Also, since benzocyclobutene becomes low in viscosity with applicationof heat treatment and reflowing properties thereof can be enhanced, theadhesive layer 9 can be spread in a wide range between the insulatinglayer 7 and the supporting substrate 30, and the close contact betweenthe insulating layer 7 and the supporting substrate 30 can be enhanced.Thus, high bonding strength can be maintained and it is possible tosuppress the occurrence of holes, voids and the like on the interfacebetween the insulating layer 7 and the supporting substrate 30.

Also, since difference in level on the surface of the insulating layer 7can be restored and the surface of the insulating layer 7 can be madeflat, the insulating layer 7 and the supporting substrate 30 can bebonded together with flatness.

Further, since the adhesive layer 9 can be prevented from being warpedconsiderably unlike the case in which the adhesive tape is in use, theprocesses following the heat treatment can be carried outsatisfactorily.

While benzocyclobutene is used as the coating film as set forth above,the present invention is not limited thereto and inorganic SOG andorganic SOG, resist, polyimide or organic resin such as polyaryl ethercan be used as the coating film.

Since such coating film is made of the material that can be cured at atemperature lower than 450° C. as described above, it is possible tosuppress a thermal influence from being exerted upon the interconnectionlayer 8 (81, 82, 83), which was previously formed on the semiconductorsubstrate 4.

Hydrogen silsequioxane (HSQ) and polysilazane (PSZ), for example, can beenumerated as the inorganic SOG, and methylsilsequioxane (MSQ), a hybridmaterial of hydrogen silsequioxane and methylsilsequioxane and the like,for example, can be enumerated as the organic SOG.

Also, resist composed of a combination of cyclized polyisoprene, anovolac resin and a photosensitizer, for example, can be enumerated asthe organic resin. Also, a resist composed of a combination of aphotoacid generator, a crosslinking agent, a PHS-based resin, a novolacresin and a methacrylic-based resin and the like, for example, can beenumerated as a chemical amplification resist.

Polyaryl ether manufactured by The Dow Chemical Company under the tradename of “SiLK” and polyaryl ether manufactured by Honeywell Inc., underthe trade names of “FLARE” and “GX-3” and the like can be enumerated asthe above-mentioned polyaryl ether.

According to this embodiment, under the bonding conditions of thereduced-pressure atmosphere of 10⁻² Torr and the heating temperature of350° C., the insulating layer 7 and the supporting substrate 30 areheated and bonded by a press treatment at a pressure of 1000N for 5minutes as set forth above.

With respect to the atmosphere, since the insulating layer 7 and thesupporting substrate 30 are heated and pressed under thereduced-pressure atmosphere in order to remove gases such as a solventproduced from the coating film, the atmosphere can be optimized inresponse to the kind of the materials for use in the adhesive layer 9.

Also, the insulating layer 7 and the supporting substrate 30 are pressedby the press treatment with pressure in order to increase the closecontact between the insulating layer 7 and the supporting substrate 30.When the thin-film forming process is carried out by the back-grindermethod, for example, in order to increase resistance against grinding,pressure of at least larger than 500N is required, preferably, pressureranging of from 500N to 2000N should be required.

Also, the heating temperature may be selected to be lower than thedeterioration starting temperature of the material (Al, Cu) forming theinterconnection layer 8 (81, 82, 83) formed on the surface side of thesingle crystal silicon layer 4, for example, the heating temperature maybe selected to be lower than 450° C., preferably, it should be selectedin a temperature range of from 350° C. to 400° C.

As described above, the conditions such as atmosphere, pressure, heatingtemperature and the like can be selected arbitrarily in response to thekind of the material for use in the adhesive layer 9.

While the coating film is used as the adhesive layer 9 to bond thesingle crystal silicon layer 4 and the supporting substrate 30 in thisembodiment, the present invention is not limited thereto and a film (CVDfilm) deposited by a CVD method can be used as the adhesive layer 9.

An SiO₂ film deposited by a plasma enhanced method (PE-CVD method), aninorganic film deposited by a low-temperature CVD method and the likemay be enumerated as this CVD film.

Further, if the CVD film is formed as the adhesive layer 9 as describedabove, then when the adhesive layer 9 is formed in the manufacturingprocess of the solid-state image pickup device 10 according to theabove-mentioned embodiment, the SiO₂ film and the organic film may beformed by the PE-CVD method and the low-temperature CVD method.

Since curing of such CVD film proceeds at a temperature of approximately400° C. similarly to the case of the above-mentioned coating film, it ispossible to suppress a thermal influence from being exerted upon theinterconnection layer 8 (81, 82, 83) made of the material with lowheat-resistance.

Also, when the film-deposition conditions of the CVD film and the likeare adjusted, reflowing properties can be enhanced similarly to the caseof the coating film. Thus, the adhesive layer 9 can be spread in a widerange between the insulating layer 7 and the supporting substrate 30 andhence the close contact between the insulating layer 7 and thesupporting substrate 30 can be increased. Therefore, since high bondingstrength between the adhesive layer 9 and the supporting substrate 30can be maintained, it is possible to suppress the occurrence of holes,voids and the like on the interface on which the adhesive layer 9 andthe supporting substrate 30 are bonded together.

Also, since the difference in level on the surface of the insulatinglayer 7 can be restored and the surface of the insulating layer 7 can bemade flat, the insulating layer 7 and the supporting substrate 30 can bebonded together with flatness.

The adhesive layer 9 is not limited thereto, and a film (silicide film)silicified by effecting the heat treatment on a metal film formed by asputtering method can be used as the adhesive layer 9.

This silicide film can be formed by silicifying an Ni film in the heattreatment done upon bonding after the Ni film was formed on the singlecrystal silicon layer 4 by the sputtering method, for example.

Also in such silicide film, since reaction between metal (Ni) andsilicon (Si) proceeds at a temperature ranging of from approximately350° C. to 450° C., it becomes possible to suppress a thermal influencefrom being exerted upon the interconnection layer 8 (81, 82, 83) made ofthe material with low heat-resistance.

Next, a semiconductor integrated circuit device according to anembodiment of the present invention will hereinafter be described withreference to FIGS. 6 and 7.

FIG. 6 is a schematic diagram (cross-sectional view) of a semiconductorintegrated circuit device and FIG. 7 is a cross-sectional view showing amain portion of FIG. 6 in an enlarged-scale.

As shown in FIGS. 6 and 7, in a semiconductor integrated circuit device40 according to this embodiment, a plurality of MOS type transistorsTr1, Tr2 are formed at predetermined positions on one side of a singlecrystal silicon layer 4, that is, surface side (in the lower side ofFIGS. 6 and 7), and a multilayer (for example, trilayer) interconnectionlayer 8A (81, 82, 83) is formed on these transistors Tr1, Tr2 through aninsulating layer 7.

Also, on the other side, that is, on the back side (in the upper side ofFIG. 7), a plurality of MOS type transistors Tr1, Tr2 are formed on thesingle crystal silicon layer 4 at its regions in which the transistorsTr1, Tr2 are formed. A multilayer (for example, trilayer)interconnection layer 8B (81, 82, 83) is formed on these transistorsTr1, Tr2 through the insulating layer 7.

Each of the MOS type transistors Tr1, Tr2 formed on the surface side andthe back side has an arrangement in which a gate electrode 6 is formedon a pair of a source region and a drain region formed in the singlecrystal silicon layer 4 through a gate insulating film.

The source region and the drain region of each of the transistors Tr1,Tr2 and a channel region are formed at the predetermined positions inthe single crystal silicon layer 4, although not shown.

Then, a supporting substrate 30 formed of a silicon substrate and thelike, for example, is bonded to the interconnection layer 8A on thesurface side through an adhesive layer 9.

Then, in the semiconductor integrated circuit device 40 according tothis embodiment, the adhesive layer 9, in particular, is made ofbenzocyclobutene similarly to the case of the above-mentionedsolid-state image pickup device.

Specific properties of benzocyclobutene are the same as those describedabove and therefore need not be described.

According to the semiconductor integrated circuit device 40 having theabove-mentioned arrangement of this embodiment, since the adhesive layer9 is made of benzocyclobutene which can be cured at a temperatureranging of from 150° C. to 250° C. which is lower than the deteriorationstarting temperature of the previously-formed interconnection layer 8A(81, 82, 83), when the supporting substrate 30 is bonded to the singlecrystal silicon layer 4 in the manufacturing process which will bedescribed later on, it becomes possible to prevent a thermal influencefrom being exerted upon the interconnection layer 8A (81, 82, 83) madeof Al or Cu with low heat-resistance even though it is processed by theheat treatment.

Also, since benzocyclobutene becomes low in viscosity and it becomeshigh in reflowing properties with application of the heat treatment, theclose contact between the insulating layer 7 and the supportingsubstrate 30 can be increased. As a result, it becomes possible tosuppress the occurrence of holes, voids and the like at the interfacebetween the insulating layer 7 and the supporting substrate 30.

Also, since the surface of the insulating layer 7, for example, can bemade flat, the insulating layer 7 and the supporting substrate 30 can bebonded together with flatness.

Next, a method of manufacturing the semiconductor integrated circuitdevice 40 having such arrangement will be described with reference toFIGS. 8A to 8G. In FIGS. 8A to 8G, elements and parts identical to thoseof FIGS. 6 and 7 are denoted by identical reference numerals.

First, as shown in FIG. 8A, the SOI substrate 5 with the single crystalsilicon layer 4 formed thereon is prepared on the silicon substrate 2,for example, through the buried oxide film (so-called BOX layer) 3.

Film thicknesses of the buried oxide film 3 and the single crystalsilicon layer 4 may be set arbitrarily.

Next, the gate electrode 6 and the MOS type transistors Tr1, Tr2, eachbeing composed of a pair of a source region and a drain region, areformed on the SOI substrate 5 at its region 27 in which each transistorof the single crystal silicon layer 4 is formed through the insulatinglayer 7, thereby exhibiting the state shown in FIG. 8B.

Next, the multilayer interconnection layer 8A (81, 82, 83) is formed onthe single crystal silicon layer 4 at its region in which thetransistors Tr1, Tr2 are formed, that is, on the surface side of thesingle crystal silicon layer 4 through the insulating layer 7, therebyexhibiting the state shown in FIG. 8C.

Specific methods of forming the respective transistors Tr1, Tr2 and theinterconnection layer 8A are similar to those of the case in which thesolid-state image pickup device according to the aforementionedembodiment is manufactured and therefore need not be described.

Next, the adhesive layer 9 is coated on the planarized film and thesupporting substrate 30 is bonded to the adhesive layer 9, therebyexhibiting the state shown in FIG. 8D.

In this embodiment, the adhesive layer 9 made of benzocyclobutene isformed and the supporting substrate 30 is bonded to the adhesive layer 9similarly to the case in which the above-mentioned solid-state imagepickup device is manufactured.

The bonding conditions are similar to those of the case in which theabove-mentioned solid-state image pickup device is manufactured andtherefore need not be described.

In that case, the adhesive layer 9 starts being cured in a lowtemperature region ranging of from 150° C. to 200° C. Thus, it ispossible to prevent a thermal influence from being exerted upon theinterconnection layer 8A (81, 82, 83) made of the material (Al or Cu)with low heat-resistance previously-formed on the semiconductorsubstrate 4.

Further, since the adhesive layer 9 is spread in a wide range of theinsulating layer 7, uneven coated portions can be prevented from beingproduced, and the close contact between the insulating layer 7 and thesupporting substrate 30 can be increased. Also, the difference in levelon the surface of the insulating layer 7 can be restored and the surfaceof the insulating layer 7 can be made flat.

Next, when the resultant product is inverted up and down, the back sideof the SOI substrate 5, that is, the silicon substrate 2 is exposed.Then, the exposed silicon substrate 2 and the buried oxide film 3 areremoved from the back side by a back-grinder method, for example, andthereby the film thickness of the semiconductor substrate is decreasedto about 15 nm to 20 nm. As a result, as shown in FIG. 8E, the singlecrystal silicon layer 4 of the SOI substrate 5 is exposed.

The film thickness of the semiconductor substrate can be decreased bynot only the back-grinder method but also other suitable method such asthe CMP method and the wet etching process. When the wet etching processis used, for example, since benzocyclobutene has high chemical resistantproperty, it is possible to prevent the adhesive layer 9 from beingcorroded (etched) by liquid medicine.

Next, the gate electrode 6 and the MOS type transistors Tr1, Tr2, eachcomposed of a pair of a source region and a drain region, are formed onthe single crystal silicon layer 4 at its position in which thetransistors Tr1, Tr2 are formed, that is, on the back side of the singlecrystal silicon layer 4 through the insulating layer 7, respectively,thereby exhibiting the state shown in FIG. 8F.

Next, the multilayer interconnection layer 8B (81, 82, 83) is formed onthe single crystal silicon layer 4 at its region in which thetransistors Tr1, Tr2 are formed through the insulating layer 7, therebyexhibiting the state shown in FIG. 8G.

Specific methods for forming the respective transistors Tr1, Tr2 and theinterconnection layer 8B are similar to those required when thesolid-state image pickup device according to the aforementionedembodiment is manufactured and therefore need not be described.

In this manner, there can be manufactured the semiconductor integratedcircuit device 40 shown in FIG. 7.

While the single crystal silicon layer 4 of the SOI substrate 5 isexposed by removing the silicon substrate 2 and the buried oxide film 3in the above-mentioned processes shown in FIGS. 8D and 8E, the presentinvention is not limited thereto and such a variant is also possible, inwhich only the silicon substrate 2 is removed, the buried oxide film(insulating film) being left.

According to the above-mentioned manufacturing method, as shown in FIG.8D, since the coating film made of benzocyclobutene is formed on theinsulating layer 7 as the adhesive layer 9 and the supporting substrate30 is bonded to the insulating layer 7 as described above, curing of thecoated film can proceed at the low temperature ranging of from 150° C.to 200° C. Consequently, it is possible to suppress a thermal influencefrom being exerted upon the interconnection layer 8A (81, 82, 83)previously formed on the semiconductor substrate 4 and which is made ofthe material with low heat-resistance.

Also, since benzocyclobutene becomes low in viscosity with applicationof the heat treatment and it becomes high in reflowing properties, theadhesive layer 9 can be spread in a wide range between the insulatinglayer 7 and the supporting substrate 30. As a consequence, since theclose contact between the insulating layer 7 and the supportingsubstrate 30 can be increased and high bonding strength can bemaintained, it is possible to suppress the occurrence of holes, voidsand the like at the interface between the insulating layer 7 and thesupporting substrate 30.

Also, since the difference in level on the surface of the insulatinglayer 7 can be restored and the surface of the insulating layer 7 can bemade flat, the insulating layer 7 and the supporting substrate 30 can bebonded together with flatness.

While benzocyclobutene is used as the adhesive layer 9 similarly to theaforementioned embodiment of the solid-state image pickup deviceaccording to this embodiment, the present invention is not limitedthereto and inorganic SOG and organic SOG and a resist, polyimide or anorganic resist such as polyaryl ether can be used.

Since these materials are those which can be cured at a temperaturelower than 450° C. as described above, it is possible to suppress athermal influence from being exerted upon the interconnection layer 8A(81, 82, 83) that was previously formed on the surface side of thesemiconductor substrate 4.

Specific kinds of inorganic SOG, organic SOG, an organic resin and thelike are similar to those of the solid-state image pickup deviceaccording to the aforementioned embodiment and therefore need not bedescribed.

Further, also in this embodiment, under the bonding conditions of thereduced-pressure atmosphere of 10⁻² Torr and the heating temperature of350° C., the insulating layer 7 and the supporting substrate 30 arebonded by the press-treatment with pressure of 1000N for 5 minutes.

However, the atmosphere, pressure, heating temperature and the like canbe arbitrarily selected in response to the kind of the material for usein the adhesive layer 9 similarly to the case in which theaforementioned solid-state image pickup device is manufactured.

Also, the film (CVD film) formed by the CVD method can be used as theadhesive layer 9 similarly to the case of the aforementioned solid-stateimage pickup device 10.

The SiO₂ film deposited by the plasma-enhanced method (PE-CVD method),the organic film deposited by the low-temperature CVD method and thelike can be used as the CVD film as mentioned hereinbefore.

As described above, if the CVD film is formed as the adhesive layer 9,then when the adhesive layer 9 is formed (see FIG. 8D) uponmanufacturing of the semiconductor integrated circuit device 40 shown inFIGS. 8A to 8G, it is sufficient that the SiO₂ film or the organic filmmay be formed by using the PE-CVD method and the low-temperature CVDmethod.

Since curing of such CVD film proceeds at a temperature of approximately400° C., it is possible to suppress a thermal influence from beingexerted upon the interconnection layer 8A (81, 82, 83) made of thematerial with low heat-resistance.

Also, when the film-deposition conditions of the CVD method and the likeare adjusted, since reflowing properties can be enhanced, as describedabove, high bonding strength between the adhesive layer 9 and thesupporting substrate 30 can be maintained and it is possible to suppressthe occurrence of holes, voids and the like on the interface between theinsulating layer 7 and the supporting substrate 30. Further, inaddition, the insulating layer 7 and the supporting substrate 30 can bebonded together with flatness.

Also, the adhesive layer 9 is not limited thereto and it is possible touse a film (silicide film) silicified by annealing the metal film formedby a sputtering method similarly to the case of the aforementionedsolid-state image pickup device 10.

This silicide film can be formed by silicifying an Ni film by the heattreatment used in the bonding process after the Ni film was formed onthe single crystal silicon layer 4 by a sputtering method, for example,in the process shown in FIG. 8D when the semiconductor integratedcircuit device 40 shown in FIGS. 8A to 8G is manufactured.

Also in such silicide film, since reaction between the metal (Ni) andthe silicon (Si) proceeds at a temperature ranging of from approximately350° C. to 450° C., it becomes possible to suppress a thermal influencefrom being exerted upon the interconnection layer 8A (81, 82, 83) madeof the material with low heat-resistance.

When the semiconductor integrated circuit device 40 according to theabove-mentioned embodiment is manufactured, we have so far described thecase in which the semiconductor integrated circuit device 40 (see FIG.6) having the arrangement in which the respective transistors Tr1, Tr2and the interconnection layers 8A, 8B are formed on the surface side andthe back side of the single crystal silicon layer 4 is manufactured, byway of example. The present invention is not limited thereto and thepresent invention can be applied to the case in which a semiconductorintegrated circuit device 41 having an arrangement in which therespective transistors Tr1, Tr2 and the interconnection layer 8A isformed on only the surface side of the single crystal silicon layer 4 asshown in FIG. 9 is manufactured.

When the semiconductor integrated circuit device 41 having theabove-mentioned arrangement is manufactured, the processes shown inFIGS. 8F and 8G, that is, the processes in which the respectivetransistors Tr1, Tr2 and the interconnection layer 8B (81, 82, 83) areformed on the back side of the single crystal silicon layer 4 need notbe carried out in the case of manufacturing the semiconductor integratedcircuit device 40 shown in FIGS. 8A to 8G.

Also in this case, in the process shown in FIG. 8D, sincebenzocyclobutene and aforementioned other respective materials are usedas the adhesive layer 9 so that curing of the adhesive layer 9 proceedsat a temperature lower than 450° C., it is possible to suppress athermal influence from being exerted upon the interconnection layer 8A(81, 82, 83) previously formed on the surface side of the single crystalsilicon layer 4 and which is made of the material with lowheat-resistance.

Also, since the close contact between the insulating layer 7 and thesupporting substrate 30 can be increased, high bonding strength can bemaintained and it is possible to suppress the occurrence of holes, voidsand the like on the interface between the insulating layer 7 and thesupporting substrate 30. Further, since the difference in level on thesurface of the insulating layer 7 can be restored and the surface of theinsulating layer 7 can be made flat, the insulating layer 7 and thesupporting substrate 30 can be bonded together with flatness.

Also, as shown in FIG. 10, the present invention can be applied to asemiconductor integrated circuit device 42 in which an interconnectionlayer 8C connected to the interconnection layer 8A through a contactinterconnection 11 is provided on the insulating layer 7 in thearrangement in which the respective transistors Tr1, Tr2 and theinterconnection layer 8A are formed on only the surface side of thesingle crystal silicon layer 4 similarly to the semiconductor integratedcircuit device 41 shown in FIG. 9.

When the semiconductor integrated circuit device 42 having theabove-mentioned arrangement is manufactured, in the case ofmanufacturing the semiconductor integrated circuit device 40 shown inFIGS. 8A to 8G, as shown in FIG. 8E, after the interconnection layer 8A(81, 82, 83) was formed on the surface side of the single crystalsilicon layer 4, the contact interconnection 11 may be formed within thesingle crystal silicon layer 4 at its position corresponding to theinterconnection layer 81, for example, and the interconnection layer 8Cmay be formed so as to be connected to this contact interconnection 11.

Also in this case, in the process shown in FIG. 8D, sincebenzocyclobutene and aforementioned other materials are used as theadhesive layer 9 so that curing of the adhesive layer 9 proceeds at atemperature lower than 450° C., it is possible to suppress a thermalinfluence from being exerted upon the interconnection layer 8 (81, 82,83) previously formed on the surface of the semiconductor substrate 4and which is made of the material with low heat-resistance.

Also, since the close contact between the insulating layer 7 and thesupporting substrate 30 can be increased, high bonding strength betweenthe insulating layer 7 and the supporting substrate 30 can be maintainedand it is possible to suppress the occurrence of holes, voids and thelike on the interface between the insulating layer 7 and the supportingsubstrate 30. Further, since the difference in level on the surface ofthe insulating layer 7 can be restored and the surface of the insulatinglayer 7 can be made flat, the insulating layer 7 and the supportingsubstrate 30 can be bonded together with flatness.

While the present invention has been described with reference to thecase in which the solid-state image pickup device and the semiconductorintegrated circuit device are manufactured from the SOI substrate 5composed of a plurality of layers in which the single crystal siliconlayers 4 are laminated on the silicon substrate 2 through the buriedoxide film (insulating film) 3, the present invention can also beapplied to the case in which the above-mentioned solid-state imagepickup device and the semiconductor integrated circuit device aremanufactured from a semiconductor substrate of a single layer.

On the other hand, the present invention can also be applied to the casein which a semiconductor integrated circuit device 45 having anarrangement shown in FIG. 11 is manufactured.

As shown in FIG. 11, in this semiconductor integrated circuit device 45,a first semiconductor integrated circuit device 43 having an arrangementin which the respective transistors Tr1, Tr2 and the interconnectionlayer 8A are formed on the surface side of the semiconductor substrate 4composed of a suitable layer such as a single crystal silicon layer anda second semiconductor integrated circuit device 44 having anarrangement in which the respective transistors Tr1, Tr2 and theinterconnection layer 8A are formed on the surface side of thesemiconductor substrate 4 are bonded together through the adhesive layer9.

Then, the interconnection layer 8A (first interconnection layer 81) ofthe first semiconductor integrated circuit device 43 and theinterconnection layer 8B (first interconnection layer 81) of the secondsemiconductor integrated circuit device 44 and the interconnection layer8C formed within the insulating layer 7 on the semiconductor substrate 4of the second semiconductor integrated circuit device 44 arerespectively connected through the contact interconnections 11.

When the semiconductor integrated circuit device 45 having theabove-mentioned arrangement is manufactured, the respective transistorsTr1, Tr2 composed of the gate electrode 6 and a pair of a source regionand a drain region and the interconnection layers 8A, 8B arerespectively formed on the surface side of the semiconductor substrate 4by a conventional method, thereby forming the first and secondsemiconductor integrated circuit device 43 and 44, although not shown.

Next, the insulating layers 7 of the first and second semiconductorintegrated circuit device 43 and 44 are opposed to each other and theyare thereby bonded together through the adhesive layer 9.

Then, after the contact interconnection 11 reaching the interconnectionlayer 8B (first interconnection layer 81) from the surface (in the upperside of FIG. 11) of the semiconductor substrate 4 of the secondsemiconductor integrated circuit device 44 and the contactinterconnection 11 reaching the interconnection layer 8A (firstinterconnection layer 81) of the first semiconductor integrated circuitdevice 43 from the surface of the semiconductor substrate 4 of thesecond semiconductor integrated circuit device 44 were respectivelyformed, they are connected to the contact interconnection 11 to form theinterconnection layer 8C.

Thus, it is possible to manufacture the semiconductor integrated circuitdevice 45 shown in FIG. 11.

In the semiconductor integrated circuit device 45 with the arrangementshown in FIG. 11, both of the two single crystal silicon layers 4 neednot always be decreased in film thickness. In this case, it is possiblethat the SOI substrate may not be used upon manufacturing.

Also in this case, since benzocyclobutene and aforementioned othermaterials are used as the adhesive layer 9 so that curing of theadhesive layer 9 can proceed at a temperature lower than 450° C., it ispossible to suppress thermal influence from being exerted upon theinterconnection layers 8A, 8B made of material with low heat-resistancein the two semiconductor integrated circuit device 43 and 44.

Also, since the semiconductor integrated circuit device 43 and 44 can bebonded together with high bonding strength, it is possible to suppressthe occurrence of holes, voids and the like on the interface between thesemiconductor integrated circuit device 43 and 44. Further, since thedifferences in level on the surfaces of the respective insulating layers7 can be restored and the surfaces of the respective insulating layers 7can be made flat, the semiconductor integrated circuit device 43 and 44can be bonded together with flatness.

The material for use with the adhesive layer 9 is not limited to thematerials of the aforementioned kinds and it can be changed freely solong as such materials can be cured at a temperature lower than thedeterioration starting temperature of the interconnection layer 8 madeof the material (for example, Al or Cu) with low heat-resistance.

According to the present invention, there is provided a method ofmanufacturing a solid-state image pickup device which is comprised of aprocess for forming a plurality of photoelectric conversion elementswithin a semiconductor substrate, a process for forming aninterconnection portion, having an interconnection layer in aninsulating layer, on the surface side of the semiconductor substrate, aprocess for forming an adhesive layer, made of a material cured at atemperature lower than a deterioration starting temperature of theinterconnection layer, on the surface side of the interconnectionportion and bonding a supporting substrate to the interconnectionportion through the adhesive layer by heat treatment at a temperaturelower than the deterioration starting temperature of the interconnectionlayer and a process for decreasing a thickness of the semiconductorsubstrate from the back side.

According to a method of manufacturing a solid-state image pickup deviceof the present invention, since this solid-state image pickup devicemanufacturing method includes the process for forming a plurality ofphotoelectric conversion elements within the semiconductor substrate,the process for forming the interconnection portion, having theinterconnection layer in the insulating layer, on the surface side ofthe semiconductor substrate and the process for forming the adhesivelayer, made of the material cured at the temperature lower than thedeterioration starting temperature of the interconnection layer, on thesurface side of the interconnection portion and bonding the supportingsubstrate to the interconnection portion through the adhesive layer byheat treatment at the temperature lower than the deterioration startingtemperature of the interconnection layer and the process for decreasingthe thickness of the semiconductor substrate from the back side, in theprocess for bonding the supporting substrate to the interconnectionportion through the adhesive layer, the adhesive layer can be cured bythe heat treatment at the temperature lower than the deteriorationstarting temperature of the interconnection layer that was formedpreviously. Thus, the supporting substrate can be bonded to theinterconnection portion through the adhesive layer without exerting athermal influence upon the interconnection layer that was previouslyformed on the surface side of the semiconductor substrate.

According to the present invention, there is provided a solid-stateimage pickup device which is comprised of a semiconductor substrate, aplurality of photoelectric conversion elements formed within thesemiconductor substrate, an interconnection portion, having aninterconnection layer in an insulating layer, formed on the surface sideof the semiconductor substrate and a supporting substrate bonded to thesurface side of the interconnection portion through an adhesive layer,wherein the adhesive layer is made of a material cured at a temperaturelower than a deterioration starting temperature of the interconnectionlayer.

According to a solid-state image pickup device of the present invention,since this solid-state image pickup device is comprised of asemiconductor substrate, a plurality of photoelectric conversionelements formed within the semiconductor substrate, the interconnectionportion, having the interconnection layer in the insulating layer,formed on the surface side of the semiconductor substrate and thesupporting substrate bonded to the surface side of the interconnectionportion through the adhesive layer, wherein the adhesive layer is madeof the material cured at the temperature lower than the deteriorationstarting temperature of the interconnection layer, upon manufacturing,the adhesive layer can be cured by the heat treatment at the temperaturelower than the deterioration starting temperature of the interconnectionlayer that was formed previously. Thus, in the process for bonding thesupporting substrate to the interconnection portion through the adhesivelayer, it is possible to protect the interconnection layer formed on thesurface side of the semiconductor substrate from being affectedthermally.

Further, according to the present invention, there is provided a methodof manufacturing a semiconductor integrated circuit device which iscomprised of a process for forming a circuit element on a semiconductorsubstrate, a process for forming an interconnection portion, having aninterconnection layer in an insulating layer, on the surface side of thesemiconductor substrate and a process for forming an adhesive layer,made of a material cured at a temperature lower than a deteriorationstarting temperature of the interconnection layer, on the surface sideof the interconnection portion and bonding a supporting substrate to theinterconnection portion through the adhesive layer by heat treatment ata temperature lower than the deterioration starting temperature of theinterconnection layer.

Further, according to a method of manufacturing a semiconductorintegrated circuit device of the present invention, since thissemiconductor integrated circuit device manufacturing method iscomprised of the process for forming the circuit element on thesemiconductor substrate, the process for forming the interconnectionportion, having the interconnection layer in the insulating layer, onthe surface side of the semiconductor substrate and the process forforming an adhesive layer, made of the material cured at the temperaturelower than the deterioration starting temperature of the interconnectionlayer, on the surface side of the interconnection portion and bondingthe supporting substrate to the interconnection portion through theadhesive layer by the heat treatment at the temperature lower than thedeterioration starting temperature of the interconnection layer, in theprocess for bonding the supporting substrate to the interconnectionportion through the adhesive layer, the adhesive layer can be cured bythe heat treatment at the temperature lower than the deteriorationstarting temperature of the interconnection layer that was formedpreviously. Thus, it is possible to bond the supporting substrate to theinterconnection portion through the adhesive layer without exerting athermal influence upon the interconnection layer that was previouslyformed on the surface side of the semiconductor substrate.

Furthermore, according to the present invention, there is provided asemiconductor integrated circuit device which is comprised of a circuitelement formed within a semiconductor substrate, an interconnectionportion, having an interconnection layer in an insulating layer, formedon the surface side of the semiconductor substrate and a supportingsubstrate bonded to the surface side of the interconnection portionthrough an adhesive layer, wherein the adhesive layer is made of amaterial cured at a temperature lower than a deterioration startingtemperature of the interconnection layer.

Furthermore, according to the semiconductor integrated circuit device ofthe present invention, since this semiconductor integrated circuitdevice is comprised of the circuit element formed within thesemiconductor substrate, the interconnection portion, having theinterconnection layer in the insulating layer, formed on the surfaceside of the semiconductor substrate and the supporting substrate bondedto the surface side of the interconnection portion through the adhesivelayer, wherein the adhesive layer is made of the material cured at thetemperature lower than the deterioration starting temperature of theinterconnection layer, upon manufacturing, the adhesive layer can becured by the heat treatment at the temperature lower than thedeterioration starting temperature of the interconnection layer that wasformed previously. Thus, in the process for bonding the supportingsubstrate to the interconnection portion through the adhesive layer, itis possible to protect the interconnection layer formed on the surfaceside of the semiconductor substrate from being affected thermally.

Furthermore, according to the solid-state image pickup devicemanufacturing method and the semiconductor integrated circuit devicemanufacturing method of the present invention, the supporting substratecan be bonded to the interconnection portion without exerting a thermalinfluence upon the interconnection layer that was formed previously.Therefore, it is possible to manufacture the solid-state image pickupdevice and the semiconductor integrated circuit device with excellentcharacteristics.

Furthermore, according to the semiconductor solid-state image pickupdevice and the semiconductor integrated circuit device of the presentinvention, when the supporting substrate is bonded to theinterconnection portion through the adhesive layer, it is possible toavoid a thermal influence from being exerted upon the previously-formedinterconnection layer. Therefore, it is possible to realize thehighly-reliable solid-state image pickup device and semiconductorintegrated circuit device with high performance.

Having described preferred embodiments of the invention with referenceto the accompanying drawings, it is to be understood that the inventionis not limited to those precise embodiments and that various changes andmodifications could be effected therein by one skilled in the artwithout departing from the spirit or scope of the invention as definedin the appended claims.

1. (canceled)
 2. (canceled)
 3. (canceled)
 4. (canceled)
 5. A solid-stateimage pickup device comprising: a semiconductor substrate; a pluralityof photoelectric conversion elements formed within said semiconductorsubstrate; an interconnection portion, having an interconnection layerin an insulating layer, formed on the surface side of said semiconductorsubstrate; and a supporting substrate bonded to the surface side of saidinterconnection portion through an adhesive layer, wherein said adhesivelayer is made of a material cured at a temperature lower than adeterioration starting temperature of said interconnection layer. 6.(canceled)
 7. (canceled)
 8. (canceled)
 9. (canceled)
 10. (canceled) 11.(canceled)
 12. A semiconductor integrated circuit device comprising: acircuit element formed within a semiconductor substrate; aninterconnection portion, having an interconnection layer in aninsulating layer, formed on the surface side of said semiconductorsubstrate; and a supporting substrate bonded to the surface side of saidinterconnection portion through an adhesive layer, wherein said adhesivelayer is made of a material cured at a temperature lower than adeterioration starting temperature of said interconnection layer.
 13. Asemiconductor integrated circuit device according to claim 12, whereinsaid substrate is composed of a circuit element formed on saidsemiconductor substrate and an interconnection portion, having aninterconnection layer in an insulating layer, formed on the surface ofsaid semiconductor substrate.